The aforementioned hydraulic antivibration device is installed, for example, on automobiles between the engine and the vehicle body frame thereof. And when a large amplitude vibration attributable to irregularity of a traveling road surface is generated, the liquid flows through the orifice to fluidize between both liquid chambers thereby damping the vibration by reason of the fluidization effect of the fluid. On the other hand, when a fine amplitude vibration is generated, the elastic partition membrane is subjected to reciprocating deformation to dampen the vibration, without the liquid flowing through between both liquid chambers.
In this type of hydraulic antivibration device, strange (unusual) sounds are liable to be generated when the elastic partition membrane impinges on the lattice members. To cope with that, hitherto the lattice members have been provided with radial ribs, as disclosed in FIG. 4 of JP Patent Publication-A-6-221368. The elastic partition membrane was constructed so that it can be situated in a spaced relation to the lattice members.
However, according to the conventional construction described above, strange sounds could be reduced to some degree, but collision sounds upon impingement of the elastic partition membrane on the ribs of the lattice members was inevitable, and hence, a problem existed in that it was not possible to reduce sufficiently strange sounds.
This invention has been made to solve the above-mentioned problem, and it is an object of the invention to provide a hydraulic antivibration device capable of reducing sufficiently strange sounds and an elastic partition membrane used for the hydraulic antivibration device.